In the art of tablet technology tablets are often made from a spray-dried powder containing an active component which after spray-drying and prior to tabletting is mixed with one or more components (for example flow-aids) needed for tabletting to take place. Flow-aids are added in order to make the powder for tabletting free-flowing. Free-flowing means that the powder may be poured through a hopper without caking or sticking to the side walls. An example of a typical flow-aid is fumed silicon dioxide.
By using this traditional method the spray-dried powder is normally very dusty and difficult to handle, so there are safety problems by handling them if the active component has an allergy potential. Often this very dusty powder also has to be handled in more than one operation: First the spray-dried powder is mixed with flow-aids as described above, and then a granulation may be needed in order to give the powder the right strength for tabletting.
To overcome these difficulties much effort has been put into developing directly compressible powders which are non-dusting and free-flowing, for instance by spray-drying an emulsion containing a vitamin, a carbohydrate and a gelatin (see U.S. Pat. No. 4,892,889).
Tablets containing enzymes such as amylases, proteases, lipases, invertases, papain, trypsin, pepsin, pancreatin, etc. have been described long ago (see for instance U.S. Pat. No. 3,515,642). They are made by the conventional methods of converting a freeze-dried or spray-dried powder into tablets.